As nouns the difference between watcher and sentry
is that watcher is someone who watches or observes while sentry is a guard, particularly on duty at the entrance to a military base.
watcher
English
Noun
(
en noun)
someone who watches or observes
someone who keeps vigil
a guard
Anagrams
*
sentry
English
Noun
(sentries)
A guard, particularly on duty at the entrance to a military base.
(uncountable) Sentry duty; time spent being a sentry.
See also
* sentinel